1hcb
From Proteopedia
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| - | [[Image:1hcb.gif|left|200px]] | + | [[Image:1hcb.gif|left|200px]] |
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| - | '''ENZYME-SUBSTRATE INTERACTIONS: STRUCTURE OF HUMAN CARBONIC ANHYDRASE I COMPLEXED WITH BICARBONATE''' | + | {{Structure |
| + | |PDB= 1hcb |SIZE=350|CAPTION= <scene name='initialview01'>1hcb</scene>, resolution 1.6Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene> and <scene name='pdbligand=BCT:BICARBONATE ION'>BCT</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''ENZYME-SUBSTRATE INTERACTIONS: STRUCTURE OF HUMAN CARBONIC ANHYDRASE I COMPLEXED WITH BICARBONATE''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1HCB is a [ | + | 1HCB is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HCB OCA]. |
==Reference== | ==Reference== | ||
| - | Enzyme-substrate interactions. Structure of human carbonic anhydrase I complexed with bicarbonate., Kumar V, Kannan KK, J Mol Biol. 1994 Aug 12;241(2):226-32. PMID:[http:// | + | Enzyme-substrate interactions. Structure of human carbonic anhydrase I complexed with bicarbonate., Kumar V, Kannan KK, J Mol Biol. 1994 Aug 12;241(2):226-32. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8057362 8057362] |
[[Category: Carbonate dehydratase]] | [[Category: Carbonate dehydratase]] | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
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[[Category: lyase(oxo-acid)]] | [[Category: lyase(oxo-acid)]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:35:22 2008'' |
Revision as of 09:35, 20 March 2008
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| , resolution 1.6Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Activity: | Carbonate dehydratase, with EC number 4.2.1.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
ENZYME-SUBSTRATE INTERACTIONS: STRUCTURE OF HUMAN CARBONIC ANHYDRASE I COMPLEXED WITH BICARBONATE
Overview
The structure of HCAI-HCO3- complex has been refined with 10-1.6A X-ray diffraction data to an R-value of 17.7%. The structure reveals monodentate binding of the HCO3- anion at an apical tetrahedral position to the zinc ion. The binding mode and interactions of HCO3- in HCAI differ from that in HCAII. The activity linked H2O/OH- group in the free HCAI is replaced by the hydroxyl group of the bicarbonate anion. This result rules out the rearrangement of the bound HCO3- advocated earlier to explain the microscopic reversibility of the catalysed reaction. From the geometry of the H-bonds between Glu106-Thr199 pair and Glu117-His119 couple, the glutamic acids are expected to be ionized and accept H-bonds from their partners. The product-inhibiton by HCO3- anion is explained on the basis of proton localization on His119 in the Glu117-His119 couple. These results are consistent with the hypothesis that Glu117-His119 tunes the ionicity of the Zn2+ and the binding strength of HCO3- anion. A pi hydrogen bond is observed between a water and phenyl ring of the Tyr114 residue.
About this Structure
1HCB is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Enzyme-substrate interactions. Structure of human carbonic anhydrase I complexed with bicarbonate., Kumar V, Kannan KK, J Mol Biol. 1994 Aug 12;241(2):226-32. PMID:8057362
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